METHOD AND INSTRUMENT FOR MEASURING ADHERING AMOUNT OF FUEL IN INTAKE PIPE

PROBLEM TO BE SOLVED: To provide a method and instrument for measuring an adhering amount of fuel in intake pipe by which an internal combustion engine can be evaluated quickly and accurately without burning the engine actually. SOLUTION: An upper cylinder chamber 9a and a lower cylinder chamber 9b which are separated form each other by a diaphragm 11 are formed in a cylinder member 9. The intake stroke of the cylinder 9 is simulated by injecting fuel into the cylinder 9 while a negative pressure flow is formed from the lower chamber 9b to the upper chamber 9a through the diaphragm 11 and causing an air flow to a hydrocarbon measuring instrument 21 through the cylinder 9, and then, the quantity hssum of the fuel consumed by combustion is measured. On the other hand, the amount of hctotal corresponding to the total injected amount of the fuel is measured by means of the measuring instrument 21 by injecting the same quantity of fuel from the valve 9 and introducing a pressurized air flow through an intake port 2-1. Therefore, the value corresponding to the amount of the fuel adhering to the internal surface of an intake pipe can be grasped by subtracting the quantity hssum from the quantity hctotal.